The tutorial discusses how to use iptables to achieve port forwarding but this limits me to having one server (instance) per port. Many of my servers have there own web interface (trac, mysql, etc) which means I must somehow create a name server that provides the desired functionality (shown above). Any suggestions?

I am now having difficulties with the iptables discussed on the last page of the tutorial. What I need to do is forward all requests on port 3306 to my sql server. Right now this is what I have in /etc/network/if-up.d/iptables